How to Share Variable Values with Multiple Buttons

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class shop:MonoBehavior {

    public DragonStatus status;
    public DeathStatus status2;
    public int Attack;
    public int shield;
    public int price;
    public int golds = 300;
    public int Button;
    public Text goldtext;

    void Start() {
        int gainAttack = Attack;
        intgainshield=shield;

        Button button=this.GetComponent<Button>();

        button.onClick.AddListener(gainItem);
    }

    void gainItem(){
        if(golds>=0){
            golds-=price;
        } else{
            Debug.Log("not enough money";
        }
    }

    public void checker() {
        string str = golds.ToString();
    }

    voidUpdateText(){
        goldtext.text="golds"+golds;
    }
}